-----------------
$g++ --version
g++ (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1)
...
$time g++ -c -Wall -pthread -fPIC dsmain.cpp
real 6m10.623s
user 6m8.142s
sys 0m0.099s
Why did the compilation took so long in user time?
Why did the compilation took so long in user time?
-----------------
$g++ --version
g++ (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1)
...
$time g++ -c -Wall -pthread -fPIC dsmain.cpp
real 6m10.623s
user 6m8.142s
sys 0m0.099s
On Wednesday March 1 2017 09:05, in comp.os.linux.development.apps, "wij@totalbb.net.tw" <wij@totalbb.net.tw> wrote:
[Text order altered]
-----------------
$g++ --version
g++ (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1)
...
$time g++ -c -Wall -pthread -fPIC dsmain.cpp
real 6m10.623s
user 6m8.142s
sys 0m0.099s
Why did the compilation took so long in user time?
You have not provided enough information to allow anyone to give you a comprehensive answer to your question.
I can give you a generic answer to your question, though.
Your compilation tool a long time because the compiler was doing lots of complicated things that didn't require any system calls.
Process time is split into "the length of time the process waited while the OS
serviced a process-initiated system call, such as open() or read()" and "the rest of the time that the process took to execute". Your "system call time" (or "sys") is 0 minutes, 0.099 seconds, while your "everything else time" (or "user") is 6 minutes, 8.142 seconds. That's all we can tell from the information you supplied.
--
Lew Pitcher
"In Skills, We Trust"
PGP public key available upon request
On 03/01/2017 03:05 PM, wij@totalbb.net.tw wrote:
Why did the compilation took so long in user time?
-----------------
$g++ --version
g++ (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1)
...
$time g++ -c -Wall -pthread -fPIC dsmain.cpp
real 6m10.623s
user 6m8.142s
sys 0m0.099s
That's g++. especially their C++ compiler is awfully slow.
Not sure what it is. maybe the parser... those STL headers
with all the templates. or their garbage collector. I
suspect it's not very good at collecting the garbage...
Maybe it is time to look for alternatives.
On Wednesday, March 1, 2017 at 10:50:14 PM UTC+8, Lew Pitcher wrote:
-----------------
$g++ --version
g++ (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1)
...
$time g++ -c -Wall -pthread -fPIC dsmain.cpp
real 6m10.623s
user 6m8.142s
sys 0m0.099s
Why did the compilation took so long in user time?
Your compilation tool a long time because the compiler was doing lots of
complicated things that didn't require any system calls.
Currently, almost every object files in the Makefile takes nearly 10 more minutes to compile. So I think it should be mostly the 'feature' of newer g++
Sysop: | Keyop |
---|---|
Location: | Huddersfield, West Yorkshire, UK |
Users: | 380 |
Nodes: | 16 (2 / 14) |
Uptime: | 52:57:17 |
Calls: | 8,144 |
Files: | 13,085 |
Messages: | 5,858,807 |